This invention relates to a weir assembly for use in a liquid-containing basin, tank or reservoir. More particularly, this invention relates to an automatically adjustable-flow floating weir assembly, which is disposed in a liquid-containing basin for regulating the flow of liquid out of the basin.
Some prior art floating weir assemblies are positioned in a body of liquid, such as a tank, and the flow of liquid through the weir assembly is always constant.
Other prior art weir assemblies are stationary in a tank, and liquid flows through such weir assemblies at a rate directly proportional to the rate at which the liquid is received in the tank.
A major problem with prior art weir assemblies is the inability to adjust the regulation of the flow of liquid out of the tank. For example, the tank in a waste water treatment plant receives a variable flow of liquid at different times during the day, and different volumes of liquid on different days. Prior art floating weir assemblies provide a constant flow of liquid and cannot be adjusted in response to different input flow conditions, such as a significantly increased volume of liquid received in the tank. Prior art stationary weir assemblies are unable to provide a constant, equalized, average volume of liquid. As a result, waste water treatment plants utilizing prior art weir assemblies have required design capacities sufficient to accommodate the highest possible flow to the tanks in the plants. This relatively high design capacity is much more expensive than the lower capacity which would suffice if the weir assemblies provided a constant, equalized volume of liquid flowing from the tank, while being adjustable to provide for a greater or lesser constant volume of liquid flowing from the tank, if desired.